By James Hibberd
November 08, 2013 at 04:23 PM EST

Glee brought out all the big diva guns Thursday night, with New Directions covering Katy Perry and Lady Gaga, plus Adam Lambert making his debut on the cast.

And yet: Ratings fell to tie the show’s all-time low, registering only 4 million viewers and a 1.5 rating in the adult demo. Glee has previously had this rating, but it was on the night before Thanksgiving last year, which in the TV ratings universe is a quasi-holiday. So this is the first time Glee has fallen this low during a non-holiday-week telecast.

Of course, baseball has pre-empted Glee in recent weeks, so the musical comedy is returning after a break. But its last episode was the highly rated Cory Monteith tribute, so last night’s episode was down 46 percent from that. Glee wasn’t helped by its lead-in: The X-Factor, was up from last week’s abysmally rated clip show, but fell to a new all-time low for a competition episode. Fox points out the episode was a “do-over” since Wednesday night’s episode had that on-screen graphics flub that messed up the voting.

Over on NBC, a special episode of The Voice swooped in to try and rescue the network’s 9 p.m. comedy block: Breathe! Breathe, damn you! It worked, at least for this week: Sean Saves the World jumped to a series high, The Michael J. Fox Show bounced to a five-week high and Parenthood hit a five-week high. Though an NFL game carried by NBC affiliate in one market could be boosting these numbers a bit. Triple-pumping The Voice this week to help the Thursday lineup impacted the musical competition series though — down 21 percent from Tuesday’s episode to rank as the show’s lowest-rated original telecast ever. Be careful NBC. Golden goose, etc.

ABC: Wonderland down 18 percent from its last original a couple weeks ago. Grey’s up 4 percent. Scandal down 7 percent to a season low. CBS: Big Bang season low, Millers and Crazy Ones both up since last week Big Bang was a repeat. Elementary down 6 percent. The CW’s Vampire Diaries jumped up 33 percent, while Reign held steady — you know, Reign‘s rating is pretty bad. But it’s freakishly consistent for a freshman drama.

FOX 8-9P X-FACTOR- 1.2 3,636
9-10P GLEE- 1.5 3,997
9-10P GREY ANATOMY- 2.7 8,552
10-11P SCANDAL- 2.7 8,586
CBS 8:00P BIG BANG- 4.8 16,588
8:30P MILLERS- 2.7 10,680
9:00P CRAZY ONES- 2.1 8,074
9:30P TWO&HLF MN- 2.0 8,144
10-11P ELEMENTARY- 1.7 8,757
NBC 8-9P VOICE S 2.7 10,233
9:00P SEAN-WORLD- 1.7 5,583
9:30P MJ FOX SHW- 1.3 4,243
10-11P PARENTHOOD- 1.5 4,530
CW 8-9P VAMPIRE DIARIES- 1.2 2,573
9-10P REIGN- 0.6 1,696